One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,5)(6,8)(9,10,14,18)(11,15,16,24)(12,21,22,20)(13,19,23,17)(25,26,30,34)(27,35,38,39)(28,32,29,33)(31,36,40,37)(2,5)(6,7)(9,11)(10,15)(12,19)(13,20)(14,16)(17,22)(18,24)(21,23)(27,36)(28,29)(31,39)(32,33)(35,40)(37,38) involution — undirected(9,12,13,15,14,22,23,24)(10,16,17,21,18,11,19,20)(25,27,28,37,30,38,29,36)(26,31,33,35,34,40,32,39)(1,3,4,8)(2,6,5,7)(11,16)(12,22)(15,24)(20,21)(25,28,30,29)(26,32,34,33)(27,37,38,36)(31,39,40,35)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.